Car is not an animal, while the others are.

Fish is the only one that lives in water, while the others are land animals.

Tree is a living organism, while the others are seasons.

Rock is not a flower, while the others are.

Car is a mode of transportation, while the others are related to healthcare.

Fire produces heat, while ice produces cold.

Fish live in water, while birds live in the air.

A flower grows in a garden, just as a fish lives in an aquarium.

A foot is part of a leg, just as a hand is part of an arm.

A hand is part of an arm, just as a foot is part of a leg.

Hot and cold are opposites, just as light and dark are opposites.

Eagle is a bird, while the others are mammals.

Oak is a tree, while the others are flowers.

Carrot is a vegetable, while the others are dairy or grain products.

Paper is a medium, while the others are tools for creating art.

Paper is not a writing instrument, while the others are.

Circle is a shape, while the others are colors.

Apple is a fruit, while the others are shapes.

The code corresponds to the position of numbers in the alphabet: 1=A, 2=B, 3=C, so 4=D, 5=E, 6=F, thus 456 is DEF.

The code reverses the order of the numbers, so '456' becomes 'FED'.

The numbers are reversed; thus 456 becomes 654.

'CAB' corresponds to '3', '1', '2' which is '321'.

'E' is the 5th letter in the alphabet, so it is coded as '5'.

B=2, A=1, D=4; thus BAD is coded as 214.

C=3, A=1, B=2; thus CAB=312.

C=3, A=1, T=20. Therefore, CAT is coded as 312.

F=6, I=9, S=19, H=8; thus FISH=614891.

Z is the 26th letter of the alphabet, so it is coded as 26.

The code is a reverse alphabet: H->S, E->V, L->O, L->O, O->L. Thus, HELLO is coded as SVOOL.

The coding is in reverse order. C is the 3rd letter, so it is coded as X (24th letter).